1. Field of the Invention
The present invention relates to an electrical plug connection including a first plug part having arranged thereat contact elements connectable to electrical lines and of a second plug part with contact elements corresponding to the contact elements of the first part in regard to arrangement and configuration whereby these contact elements are, for example, contact pins and/or contact sockets. When the plug connection is completed, the contact elements rest against one another so as to establish electrical contact, and the two plug parts are locked against accidental or arbitrary separation. A wire spring is supported at one of the plug parts to provide a locking function for the two plug parts. It has at least one spring leg that is deflected by the relative movement of the two plug parts toward one another required for producing the electrical plug connection. The spring leg is deflected in the plane parallel to the moving direction of the parts for producing the plug connection as well as transverse to that plane.
2. Description of the Related Art
Plug connections for different applications are known in which the parts to be connected to one another can be locked relative to one another by a spring catch. Without claiming to provide a complete review, reference is made to the known device for securing an electrical or electronic component at a housing according to European patent document 0 727 850 A, respectively, the substantially identical disclosure of German patent document 195 04 821 C2; the securing holder for a solenoid coil according to U.S. Pat. No. 5,025,682; or the connecting coupling according to U.S. Pat. No. 3,753,582. The springs used in these devices are deflected transversely to the direction in which the parts to be connected are moved for producing the desired plug connection. When the parts to be connected are completely inserted, the transversely deflected spring engages a groove and thus forms a locking bolt arrangement which prevents accidental or arbitrary separation of the connected parts. When the parts to be connected are not completely inserted, the connection is not only insufficient but, moreover, the spring cannot perform the desired locking function. In electrical plug connections that are to be used in monitoring circuits and can no longer be accessed or accessed only with difficulty after their installation in a device, an incomplete connection may result in disastrous consequences.
From Japanese patent document 10-189145 A another electrical plug connection is known in which the plug parts automatically separate if the parts forming the plug connection have been incompletely inserted into one another, i.e., without producing optimal contacting, and the plug connection is not locked. For this purpose a U-shaped wire spring is provided having two lateral legs with additional S-shaped and compressible portions. Upon insertion of the two parts of the plug connection, the two lateral legs as well as the base leg connecting the two lateral legs are compressed. Subsequently, the forward arc-shaped end of the U-shaped spring is upwardly deflected and lifted above the abutment surface at the other plug part which compresses the U-shaped spring. The compression of the U-shaped spring is thus released and the spring can move into its locking position in which it engages behind a projection at the other plug part. The disadvantage of this plug connection is that the plug is relative large with respect to its height and its axial longitudinal extension. A size reduction of the plug connection in the axial direction has limits especially because of the space requirements of the U-shaped spring which must be provided with a sufficient compressibility in the axial direction. However, for certain applications, the space that is available for a plug is very limited.